Field of the Invention
The present invention relates to a display apparatus and a method of manufacturing the same, and more particularly, to a display apparatus having a circular display portion.
Discussion of the Related Art
Generally, display apparatuses have been widely used as the screens of various products such as televisions, notebook computers and monitors as well as portable electronic devices such as mobile communication terminals, electronic diaries, electronic books, portable multimedia players (PMPs), navigation systems, ultra mobile PCs (UMPCs), mobile phones, smart phones, tablet PCs (personal computers) and watch phones.
Studies for developing flexible display apparatuses have been made, focusing on liquid crystal display apparatuses, organic light emitting display apparatuses and electrophoretic display apparatuses due to their slim sizes.
An organic light emitting display apparatus displays a desired picture image by controlling an amount of current that flows from a pixel power line to the organic light emitting diode in accordance with a data signal. Such an organic light emitting display apparatus typically has a rectangular display screen due to arrangement structures of signal lines, pixel driving power lines and driving circuits.
Recently, as appearance and design of display apparatuses have become more important and consumers' attention to wearable devices such as watch phones has increased, studies and developments of a display apparatus having a circular display screen, not a rectangular display screen, have been made.
FIG. 1 is a cross-sectional view illustrating some parts of a display apparatus having a circular display portion according to the related art.
Referring to FIG. 1, the display apparatus having a circular display portion according to the related art is formed of a plastic material. The display apparatus includes a substrate 10 having a circular display area (DA) and a non-display area (NDA) in a periphery of the display area (DA), the display portion 20 in the display area (DA) of the substrate 10, a pad 30 at one side of the non-display area (NDA) of the substrate 10, a flexible printed circuit board 40 attached to the pad 30 and provided to supply signals to the display portion 20 through the pad 30, a barrier film 50 on the display portion 20 that is provided to cover an upper surface of the substrate 10 except the pad 30, a polarizing film 60 attached to an upper surface of the barrier film 50, a cover window 70 attached to an upper surface of the polarizing film 60 by the use of transparent adhesive 65 and provided to cover the upper surface of the substrate 10, and a resin coating layer 80 coated and cured at a connection portion between the flexible printed circuit board 40 and the pad 30 of the substrate 10.
The display portion 20 may include an organic light emitting diode (not shown) and a pixel circuit (not shown) that controls the organic light emitting diode to emit light in accordance with a signal supplied from the flexible printed circuit board 40 via the pad 30.
A gap space (GS) may exist between the substrate 10 and the cover window 70 at a driving circuit connecting portion of the display apparatus according to the related art. The gap space (GS) at the driving circuit connecting portion may facilitate connecting the flexible printed circuit board 40 with the pad 30 of the substrate 10, attaching the polarizing film 60 and coating the transparent adhesive 65 during the manufacturing processes.
The gap space (GS) may cause micro-cracks to occur on the substrate 10 due to an external force, such as bonding force or adhering force applied to the substrate 10, during a direct bonding process for attaching the cover window 70 to the upper surface of the polarizing film 60, thereby lowering reliability of the substrate 10.
The gap space (GS) may be sealed by the resin coating layer 80 used to improve adhesiveness between the flexible printed circuit board 40 and the pad 30 of the substrate 10. However, it may be difficult to fill the resin coating layer 80 in the gap space (GS). Also, if a thickness of the resin coating layer 80 increases, a processing time for curing the resin coating layer 80 increases, thereby decreasing productivity. Moreover, the resin coating layer 80 filled in the gap space (GS) may spread during the attachment process of the cover window 70, which may contaminate a peripheral area of the display apparatus. In order to prevent such a contamination at the peripheral area, an additional process such as forming a separate dam structure may be needed.
The above description for the display apparatus having the circular display portion using the organic light emitting diode is technical information which was possessed by the inventor when deriving some or part of the present invention. Thus, the above description may not be prior art.